Innovative Strategies for Designing Metallic Compounds in Electrocatalytic Nitrate-to-Ammonia Reduction

The nitrogen cycle exposes humans to significant risks due to the substantial rise in nitrate levels in global groundwater. The electrocatalytic reduction of nitrate to ammonia (eNRA) offers a dual benefit: mitigating nitrate accumulation in water bodies and fostering the development of ammonia-based hydrogen carriers. In this review, we examine recent progress in eNRA research, focusing on reaction pathways/mechanisms, performance testing, and catalysts development. We begin with an overview of recent applications of metallic and nonmetallic catalysts in eNRA. Next, we discuss three extensively studied reaction pathways, detailing their identification methods and processes. From a catalyst design perspective, we review advancements in metallic compound catalysts, highlighting their advantages and limitations. Finally, we provide insights into the further directions and challenges in this field. This review aims to serve as a valuable resource for designing advanced cathodic electrocatalysts, driving the sustainable utilization and production of renewable resources.